NY 308 is a short/east route located near the northwest corner of Dutchess County. It begins at US 9 at the point in Rhinebeck where it changes names from Mill Street to Montgomery Street. In the Village of Rhinebeck, it is known as East Market Street, but it loses the name and is known solely by its number after leaving the village. After about a mile, it crosses NY 9G at a grade-separated interchange. It then continues northeast to Red Hook, where it merges with NY 199 and ends.